Currently there are no reliable pharmacologic treatments for cocaine addiction. An alternate approach is to block access of cocaine to the central nervous system by the generation of anti-cocaine antibody. The goal of this research is to determine the feasibility of an active immunization approach to prevent relapse in cocaine addiction. Cocaine or cocaine derivatives will be used to haptenate defined carriers. These conjugates will be used to immunize mice. If high titer cocaine-specific antibody can be generated which blocks toxic effects upon cocaine challenge it suggests antibody elicited via immunization can block CNS mediated re-inforcing properties of cocaine. The ability of defined conjugate immunization to alter self-addiction in animal models will be studied in Phase II. Provided efficacy in animal models is demonstrated, immunization with defined conjugates can be tested in concert with current substance abuse treatment programs for its ability to prevent relapse in cocaine addiction in humans within 3-4 years.